This shy guy crushing on me flirt with other girls infront of me. If I suddenly leave to go on vacation, DO YOU GUYS THINK HE WILL MISS ME?

Yes he will! He is shy and insecure, so what he is doing to attract you is totally wrong. What he is supposed to do is flirt with you, but he is too nervous to do it to someone as beautiful as you that he wants to make you jealous. It might be harsh, but hey, at least you seem more special now. He will miss you if you even leave for a day, thinking on how to make you more jealous so that you can fight for him, or simply give up on his chances of dating you.
Good luck ✌🏻️

no guys are all players....even the shy ones do....I say date someone that really truly cares for you....

No.